Various types of strand fabricating, braiding machines, or the like have been known for many years. Machines of this type have in common the use in different arrangements of a plurality of bobbin posts for mounting a cop or tube on which stranding of thread, yarn, or roving of various types of natural or synthetic materials are wound for payout in a controlled manner during operation of the machinery. Characteristically, the bobbin posts are mounted on and non-rotatably attached to a freely-rotatably mounted spindle for effecting payout of the stranding wound on the cop in a controlled manner. Over the years, many devices have been employed to effect retention of a cop on a bobbin post, such as to allow demounting and mounting of a cop with respect to a bobbin post when the strand material on the cop is exhausted or when a cop having a full supply of strand material is to be loaded, respectively.
For many years, cop locking mechanisms were commonly in the form of a plurality of circumferentially-spaced spring members which normally define a circumference greater than the diameter of the central bore of a mating cop. When the cop bore was inserted over the springs of the bobbin posts, the springs collapsed to maintain a strong frictional engagement with the bore of the cop. In many instances, it was difficult to achieve a design of the springs of which there were many which would maintain the cops in the precise position required on the bobbin posts during the operating motions of strand fabricating or braiding machines. In addition, the springs would frequently exhibit wear characteristics due to the highly repetitious mounting and demounting of cops incident to operation of the machines, such that the cops were not appropriately axially restrained on the bobbin posts and would become axially displaced during operation of the machines. Efforts have been made to design somewhat oversized or over-tensioned springs to preclude axial release of the cops during operation of the machines. However, these designs commonly required the machine operator to exert extreme amounts of force in order to effect the mounting and demounting of cops, thus having detrimental effects on the production rates of machines having bobbin posts with such spring constructions.
Until relatively recently, cops for strand materials have normally been constructed of cardboard or similar materials which can be depressed or cut relatively easily. As a result, many current designs have employed a type of spring steel having some type of blade configuration that is designed to dig into the cop in the bore area to enhance retention of the cop on a bobbin post provided with such biased blades. Devices of this type continue to suffer the disadvantage that it is often difficult in terms of exerting large forces to mount and demount the cops on bobbin posts having such locking mechanisms. While bobbin posts having such blade mechanisms are often effective to prevent relative rotation between the bobbin posts and the cop, some of such blade designs are not effective to prevent axial movement of a cop relative to a bobbin post having such a blade configuration. As a result, many of the designs employing such a spring blade also require a second, separate latch mechanism which is actuated to prevent the cop from being displaced axially of the bobbin post. Such latch mechanisms frequently take the form of a bar mounted at the axially outer extremity of the bobbin post, which is pivotal between a position aligned with the post for receiving a cop as an open position to a closed position effected by rotating the bar through 90.degree., such that it resides perpendicular to the bobbin post just axially outwardly of the cop when it is in the operating position on the bobbin post. Such latch mechanisms have the disadvantage of requiring a second operation by a machine operator in both mounting and demounting cops on the bobbin post, as well as independent verification that the latch is open when a cop is to be mounted and that the latch is locked upon mounting a cop before actuation of the machine.
Due to the disadvantages of the aforedescribed springs, leaves, and blades, some current designs have employed a plurality of projecting circumferentially-spaced fixed drive keys extending longitudinally of the bobbin posts, which are engaged by specially designed cops which have a plurality of mating circumferentially-spaced longitudinal grooves within the throughbore of the cop. While these key drives do provide positive rotational interaction between the cop and the bobbin post, they do require that the machine operator take additional time to grasp the bobbin post and restrain it while the cop grooves are aligned with the bobbin post keys before the cops can be mounted on the bobbin posts. These fixed key drive designs also require a separate latch mechanism to secure the cop axially of the bobbin post.
Summarily, existing and prior cop locking mechanisms have suffered either operational shortcomings or have required excessive operator time and manipulation to effect mounting and demounting of cops on bobbin posts. As a result, none of the existing designs have achieved widespread acceptance in the industry.